dev-python/grpcio: respect CC in setup.py

Upstream-PR: https://github.com/grpc/grpc/pull/23159
Bug: https://bugs.gentoo.org/727478
Package-Manager: Portage-2.3.100, Repoman-2.3.22
Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org>

dev-python/grpcio/files/setup.py-respect-cc.patch

@@ -0,0 +1,33 @@
+From 0a6c58fc0161e697bbf64b4f3d4ef14b03ac186b Mon Sep 17 00:00:00 2001
+From: Georgy Yakovlev <gyakovlev@gentoo.org>
+Date: Sun, 7 Jun 2020 23:35:31 -0700
+Subject: [PATCH] setup.py: respect CC variable in latomic test
+
+some configurations do not provide generic cc binary.
+while rest of the build calls CHOST prefixed binaries,
+this check fails. fix it.
+
+Signed-off-by: Georgy Yakovlev <gyakovlev@gentoo.org>
+---
+ setup.py | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/setup.py b/setup.py
+index 2379703eb7..0f92270607 100644
+--- a/setup.py
++++ b/setup.py
+@@ -144,9 +144,10 @@ ENABLE_DOCUMENTATION_BUILD = os.environ.get(
+
+ def check_linker_need_libatomic():
+   """Test if linker on system needs libatomic."""
++  cc = os.environ.get('CC', 'cc')
+   code_test = (b'#include <atomic>\n' +
+                b'int main() { return std::atomic<int64_t>{}; }')
+-  cc_test = subprocess.Popen(['cc', '-x', 'c++', '-std=c++11', '-'],
++  cc_test = subprocess.Popen([cc, '-x', 'c++', '-std=c++11', '-'],
+                              stdin=PIPE,
+                              stdout=PIPE,
+                              stderr=PIPE) 
+-- 
+2.27.0
+

dev-python/grpcio/grpcio-1.28.1.ebuild

@@ -25,6 +25,8 @@ DEPEND="${RDEPEND}
 	dev-python/setuptools[${PYTHON_USEDEP}]
 "
 
+PATCHES=( "${FILESDIR}/setup.py-respect-cc.patch" )
+
 python_configure_all() {
 	export GRPC_PYTHON_DISABLE_LIBC_COMPATIBILITY=1
 	export GRPC_PYTHON_BUILD_SYSTEM_CARES=1